Panman, you trying to give us few Oregonians a bad name? Wait, I'VE already, done that, never mind!

Raw; My "primary" use for eyes when I do use them, is to place all the weight I may want on a leach/bait fish pattern, say, "up front" so when retrieved the fly rises and falls, more like the leech it's imitating. It also saves on putting lead or non-lead,wire, on the hook shank which will make the fly sink in a more "parallel fashion" which leeches just don't swim in. Or, bait fish, for that matter.
"Colors", depends on color of the fly and also on water clarity.